.tt{
    margin:20px auto;
    width:800px;
    border-collapse: collapse;
}
.tt tr td,.tt tr th{
    border: 1px solid #ededed;
    padding: 8px;
    text-align: center;
    font:16px/25px "微软雅黑"
}
.tt tr:hover{
    background-color: #d6e0b4;
}